1. Field of the Invention
This invention relates in general to computer-implemented database systems, and, in particular, to user-defined search in Relational Database Management Systems.
2. Description of Related Art
Databases are computerized information storage and retrieval systems. A Relational Database Management System (RDBMS) is a database management system (DBMS) which uses relational techniques for storing and retrieving data. Relational databases are organized into tables which consist of rows and columns of data. The rows are formally called tuples or records. A database will typically have many tables and each table will typically have multiple tuples and multiple columns. The tables are typically stored on direct access storage devices (DASD), such as magnetic or optical disk drives for semi-permanent storage.
Many traditional business transaction processing is done using a RDBMS. Since the inclusion of RDBMSs in business, user-defined data types and user-defined functions have been brought into RDBMSs to enrich the data modeling and data processing power. User-defined data based on the user-defined data types may include audio, video, image, text, spatial data (e.g., shape, point, line, polygon, etc.), time series data, OLE documents, Java objects, C++ objects, etc.
The most important features for RDBMSs are storing information efficiently and reliably and retrieving the stored information within the response criteria with high efficiency. A major challenge for RDBMSs is to provide a model and implement a technique so that user-defined data (i.e., data which is based on user-defined types and which is not known to the RDBMS when the RDBMS is built) qualified by user-defined functions (i.e., functions that are defined by a user and that are not known to the RDBMS when the RDBMS is built) can be located quickly and efficiently. It is extremely important that the model takes a consistent approach with the existing RDBMS search technique, so that the model can take advantage of the existing RDBMS and can be easily integrated into the existing RDBMS.
Therefore, there is a need in the art for an improved model for user-defined search in Relational Database Management Systems.